You can select an element, its content or any document portion in the ContentMap or Editing Window and move it to another location.
To drag&drop some content, do the following:
Figure 1. Element selected in the Editing Window.
Drag the selected content and drop it at the desired place in the ContentMap or the Editing Window.
Figure 2. The element has been moved to another location.
Serna shows you where dropping of the dragged content is allowed.
If you drop on the ContentMap item, the content is dropped at the beginning of this element (before its content if any).